Acoustic panels and methods for preparing them

ABSTRACT

The disclosure relates to acoustic panels and methods for preparing them. The disclosure relates more particularly to panels having a nonwoven facing and to methods for making such panels. A method for preparing an acoustic panel comprises providing a base structure. The base structure has one or more edges, an outward major surface having total area, and an inward major surface opposing the outward major surface. The base structure has a noise reduction coefficient (NRC) of at least about 0.3. The method includes disposing directly against the outward major surface of the base structure a sprayable mixture comprising a plurality of fibers, one or more binders, and a dispersive medium. The method includes drying the disposed mixture to provide a facing layer disposed on the outward major surface of the base structure, the facing layer having an exterior major surface opposing the outward major surface of the base structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalPatent Application No. 62/699,565, filed Jul. 17, 2019, which is herebyincorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The disclosure generally relates to acoustic panels and methods forpreparing them. The disclosure relates more particularly to panelshaving a nonwoven facing and to methods for making such panels.

Description of Related Art

Acoustic panels are useful in a number of applications to attenuatenoise. For example, an interior ceiling structure can include a systemof sound absorbing panels installed on a metal grid. The grid issuspended below a structural ceiling of a room to create a plenum, orair space, between the rear surface of the panels and the ceiling. Thefront sides of the panels are viewed from below as a dropped ceiling ofthe room.

Acoustic panels suitable for a ceiling structure typically comprise alightweight material such as mineral wool, gypsum, foam, wood fiber,paper, cellulose fiber, wet-laid felt, or fiberglass. The panels can beperforated to achieve a desired acoustic absorbency. Perforating opensthe plane surface and the internal structure of the acoustic panel toallow air and sound waves to move in and out of the panel.

The physical features of conventional acoustic panels such as, forexample, porous fiberglass panels or perforated mineral wool panels, aretypically visible, for example, when viewed from below as part of adropped ceiling of a room. Conventional methods for obscuring thephysical features of acoustic panels involve laminating a facing ontothe panel, but such methods are limited, in large part because mostcoverings decrease the acoustic performance of the panel. Moreover,conventional facings are not cost-effective. For example, in the case ofa conventional glass mat facing for an acoustic panel, the facing isformed with an expensive formaldehyde-free binder, the laminationprocess is itself costly, and the weight and fragility of the panelsafter lamination increases.

Accordingly, there remains a need for a lightweight acoustic panelhaving an acoustically transparent facing, and for a simple,cost-effective method for preparing such panels.

SUMMARY OF THE DISCLOSURE

In one aspect, the present disclosure provides a method for preparing anacoustic panel comprising

-   -   providing a base structure having one or more edges, an outward        major surface having a total area, and an inward major surface        opposing the outward major surface, the base structure having        independently a noise reduction coefficient (NRC) of at least        about 0.3; and    -   disposing directly against the outward major surface of the base        structure a sprayable mixture comprising        -   a plurality of fibers;        -   one or more binders; and        -   a dispersive medium; and    -   drying the disposed mixture to provide a facing layer disposed        on the outward major surface of the base structure, the facing        layer having an exterior major surface opposing the outward        major surface of the base structure.

In another aspect, the present disclosure provides an acoustic panelmade by the method of the disclosure.

In another aspect, the present disclosure provides an acoustic panelcomprising:

-   -   a base structure having one or more edges, an outward major        surface having a total area, and an inward major surface        opposing the outward major surface, the base structure having        independently an NRC of at least about 0.3; and    -   a facing layer directly disposed on the outward major surface of        the base structure, the facing layer comprising a plurality of        fibers and one or more binders, the facing layer having an        exterior major surface opposing the outward major surface of the        base structure.

In another aspect, the present disclosure provides a panel systemcomprising:

-   -   a plurality of support beams arranged in a support grid so as to        form a plurality of grid openings in the support grid; and    -   a plurality of panels respectively aligned with the openings of        the support grid, the plurality of panels including a first        acoustic panel according to any of claims 33-50, wherein the        first acoustic panel is oriented such that the exterior major        surface of the facing layer is facing an interior space adjacent        to the support grid.

Other aspects of the disclosure will be apparent to the person ofordinary skill in the art based on the drawings and detailed descriptionbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an image of an acoustic panel comprising a facing layeraccording to one embodiment of the disclosure;

FIG. 2A shows a facing layer according to an embodiment of thedisclosure after drying having a paint coating of about 30 g/m²;

FIG. 2B shows a facing layer according to an embodiment of thedisclosure after drying having a paint coating of about 100 g/m²; and

FIG. 2C shows a facing layer according to an embodiment of thedisclosure after drying having a paint coating of about 175 g/m².

DETAILED DESCRIPTION OF THE DISCLOSURE

The particulars shown herein are by way of example and for purposes ofillustrative discussion of the preferred embodiments of the presentinvention only and are presented in the cause of providing what isbelieved to be the most useful and readily understood description of theprinciples and conceptual aspects of various embodiments of theinvention. In this regard, no attempt is made to show structural detailsof the invention in more detail than is necessary for the fundamentalunderstanding of the invention, the description taken with the drawingsand/or examples making apparent to those skilled in the art how theseveral forms of the invention may be embodied in practice. Thus, beforethe disclosed processes and devices are described, it is to beunderstood that the aspects described herein are not limited to specificembodiments, apparatuses, or configurations, and as such can, of course,vary. It is also to be understood that the terminology used herein isfor the purpose of describing particular aspects only and, unlessspecifically defined herein, is not intended to be limiting.

The terms “a,” “an,” “the” and similar referents used in the context ofdescribing the invention (especially in the context of the followingclaims) are to be construed to cover both the singular and the plural,unless otherwise indicated herein or clearly contradicted by context.Recitation of ranges of values herein is merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range. Unless otherwise indicated herein, eachindividual value is incorporated into the specification as if it wereindividually recited herein. Ranges can be expressed herein as from“about” one particular value, and/or to “about” another particularvalue. When such a range is expressed, another aspect includes from theone particular value and/or to the other particular value. Similarly,when values are expressed as approximations, by use of the antecedent“about,” it will be understood that the particular value forms anotheraspect. It will be further understood that the endpoints of each of theranges are significant both in relation to the other endpoint, andindependently of the other endpoint.

All methods described herein can be performed in any suitable order ofsteps unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein is intended merely to betterilluminate the invention and does not pose a limitation on the scope ofthe invention otherwise claimed. No language in the specification shouldbe construed as indicating any non-claimed element essential to thepractice of the invention.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words ‘comprise’, ‘comprising’, and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to”. Words using the singular or pluralnumber also include the plural and singular number, respectively.Additionally, the words “herein,” “above,” and “below” and words ofsimilar import, when used in this application, shall refer to thisapplication as a whole and not to any particular portions of theapplication.

As will be understood by one of ordinary skill in the art, eachembodiment disclosed herein can comprise, consist essentially of orconsist of its particular stated element, step, ingredient or component.As used herein, the transition term “comprise” or “comprises” meansincludes, but is not limited to, and allows for the inclusion ofunspecified elements, steps, ingredients, or components, even in majoramounts. The transitional phrase “consisting of” excludes any element,step, ingredient or component not specified. The transition phrase“consisting essentially of” limits the scope of the embodiment to thespecified elements, steps, ingredients or components and to those thatdo not materially affect the embodiment.

Unless otherwise indicated, all numbers expressing quantities ofingredients, properties such as molecular weight, reaction conditions,and so forth used in the specification and claims are to be understoodas being modified in all instances by the term “about.” Accordingly,unless indicated to the contrary, the numerical parameters set forth inthe specification and attached claims are approximations that may varydepending upon the desired properties sought to be obtained by thepresent invention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques. When further clarity is required, the term “about” has themeaning reasonably ascribed to it by a person skilled in the art whenused in conjunction with a stated numerical value or range, i.e.,denoting somewhat more or somewhat less than the stated value or range,e.g., to within a range of ±20% of the stated value; ±19% of the statedvalue; ±18% of the stated value; ±17% of the stated value; ±16% of thestated value; ±15% of the stated value; ±14% of the stated value; ±13%of the stated value; ±12% of the stated value; ±11% of the stated value;±10% of the stated value; ±9% of the stated value; ±8% of the statedvalue; ±7% of the stated value; ±6% of the stated value; ±5% of thestated value; ±4% of the stated value; ±3% of the stated value; ±2% ofthe stated value; or ±1% of the stated value.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements.

Groupings of alternative elements or embodiments of the inventiondisclosed herein are not to be construed as limitations. Each groupmember may be referred to and claimed individually or in any combinationwith other members of the group or other elements found herein. It isanticipated that one or more members of a group may be included in, ordeleted from, a group for reasons of convenience and/or patentability.When any such inclusion or deletion occurs, the specification is deemedto contain the group as modified thus fulfilling the written descriptionof all Markush groups used in the appended claims.

Some embodiments of this invention are described herein, including thebest mode known to the inventors for carrying out the invention. Ofcourse, variations on these described embodiments will become apparentto those of ordinary skill in the art upon reading the foregoingdescription. The inventor expects skilled artisans to employ suchvariations as appropriate, and the inventors intend for the invention tobe practiced otherwise than specifically described herein. Accordingly,this invention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

As the person of ordinary skill in the art will appreciate, directionssuch as “vertical,” “horizontal,” “upper” and “lower” are definedrelative to how the support member is to be installed, with the ceilingdefined as “up.”

Furthermore, numerous references have been made to patents and printedpublications throughout this specification. Each of the cited referencesand printed publications are individually incorporated herein byreference in their entirety.

In closing, it is to be understood that the embodiments of the inventiondisclosed herein are illustrative of the principles of the presentinvention. Other modifications that may be employed are within the scopeof the invention. Thus, by way of example, but not of limitation,alternative configurations of the present invention may be utilized inaccordance with the teachings herein. Accordingly, the present inventionis not limited to that precisely as shown and described.

In various aspects and embodiments, the disclosure relates to a methodfor preparing an acoustic panel. The disclosure demonstrates suchmethods to efficiently provide relatively inexpensive and lightweightacoustic panels having a facing layer that is transparent to sound andobscuring of a base structure. One aspect of the disclosure is a methodfor preparing an acoustic panel comprising providing a base structure.The base structure has one or more edges, an outward major surfacehaving a total area, and an inward major surface opposing the outwardmajor surface. The base structure has independently a noise reductioncoefficient (NRC) of at least about 0.3. The method includes disposingdirectly against the outward major surface of the base structure asprayable mixture comprising a plurality of fibers, one or more binders,and a dispersive medium. The method includes drying the disposed mixtureto provide a facing layer disposed on the outward major surface of thebase structure, the facing layer having an exterior major surfaceopposing the outward major surface of the base structure. The inventorshave determined that the method provides a relatively lightweight facinglayer without requiring separate facing layer formation and laminationsteps.

One embodiment of the disclosure is shown in schematic view in FIG. 1. Aprimary component of the panel 10 is a base structure 12. The basestructure 12 has an outward major surface 14, an inward major surface16, and edges 18. In certain embodiments as otherwise described herein,the base structure comprises one or more of mineral wool, fiberglass,gypsum, wood fiber, paper, cellulose fiber, wet-laid felt, and foam. Incertain such embodiments, the base structure comprises one or morefillers, and one or more binders. For example, in certain embodiments asotherwise described herein, the mineral wool, fiberglass, gypsum, woodfiber, paper, cellulose fiber, wet-laid felt, and/or foam, and the oneor more fillers and one or more binders are present in the basestructure in a combined amount of at least 85 wt. %, or at least about90 wt. %, or at least about 95 wt. %, or at least about 97.5%, or atleast about 99 wt. %, or at least about 99.5 wt. %. In certainembodiments as otherwise described herein, the base structure comprisesmineral wool. The person of ordinary skill in the art will appreciatethat a number of fillers suitable for a base structure (e.g., a basestructure comprising mineral wool) are known in the art. For example, incertain embodiments as otherwise described herein, the base structurecomprises one or more fillers selected from dolomite, wollastonite, sawdust, fly ash, recycled plastic, rubber crumb, gypsum, glass, perlite,wood pulp (i.e., cellulose), recycled paper, and recycled glass. Theperson of ordinary skill in the art will further appreciate that anumber of binders suitable for a base structure (e.g., a base structurecomprising mineral wool) are known in the art. For example, in certainembodiments as otherwise described herein, the base structure comprisesone or more binders selected from urea-formaldehyde resin, phenolicresin, polyurethane, polyacrylates, polystyrene, styrene-acrylatecopolymers, styrene-butadiene copolymers (i.e., styrene-butadienerubber, SBR), styrene-butadiene-styrene block copolymer (SBS),styrene-ethylene-butadiene-styrene block copolymer (SEBS), poly(vinylacetate) (PVAc), poly(vinyl alcohol) (PVA), poly(ethylene-vinyl acetate)(EVA), silicone, nylon, acetal, polyethylene oxide, acrylic resin, andstarch.

In certain embodiments as otherwise described herein, the base structuredoes not comprise perforations. For example, in certain suchembodiments, the base structure has one or more physical properties(e.g., porosity) that provide desirable acoustic properties.

In other embodiments, the base structure comprises a plurality ofperforations extending from the outward major surface towards the inwardmajor surface, the plurality of perforations occupying an area of theoutward major surface. As used herein, the shape of a perforation at itsopening may be elongated (e.g., may have an aspect ratio of 2, or 3, or4, or 5, etc.), or may be annular (e.g., circular). In certainembodiments as otherwise described herein, the perforations have anaverage depth of less than about 4 mm. For example, in certain suchembodiments, the perforations have an average depth within the range ofabout 2 mm to about 4 mm. In other embodiments, the perforations have anaverage depth of at least about 4 mm. For example, in certain suchembodiments, the perforations have an average depth within the range ofabout 4 mm to about 12 mm. The person of ordinary skill in the art willappreciate that, in some aspects, perforations as used herein, having anelongated opening and an average depth of less than about 4 mm are alsoknown in the art as “fissures.”

Base structure 12 comprises a plurality of perforations 20 (shown inpart in FIG. 1). In certain embodiments as otherwise described herein,the plurality of perforations occupies an area of the outward majorsurface that is within the range of about 0.1% to about 10% of the totalarea of the outward major surface of base structure 12. For example, incertain embodiments as otherwise described herein, the perforationsoccupy an area of the outward major surface within the range of about0.1% to about 9%, or about 0.1% to about 8%, or about 0.1% to about 7%,or about 0.1% to about 6%, or about 0.1% to about 5%, or about 0.1% toabout 4%, or about 0.25% to about 10%, or about 0.5% to about 10%, orabout 0.75% to about 10%, or about 1% to about 10%, or about 1.5% toabout 10%, or about 2% to about 10%, or about 2.5% to about 10%, orabout 3% to about 10%, or about 4% to about 10%, or about 5% to about10%, or about 6% to about 10%, or about 7% to about 10%, or about 0.25%to about 9%, or about 0.5% to about 8%, or about 0.75% to about 7%, orabout 1% to about 6%, or about 1.5% to about 5% of the total area of theoutward major surface.

In certain embodiments as otherwise described herein, the perforationshave an average depth of at least about 4 mm, such as an average depthwithin the range of about 4 mm to about 12 mm, or about 5 mm to about 10mm. In certain embodiments as otherwise described herein, the pluralityof perforations are annular, and the perforations have an averagediameter within the range of about 0.25 mm to about 5 mm. For example,in certain such embodiments, the average diameter of the perforations iswithin the range of about 0.25 mm to about 4.5 mm, or about 0.25 mm toabout 4 mm, or about 0.25 mm to about 3.5 mm, or about 0.25 mm to about3 mm, or about 0.25 mm to about 2.5 mm, or about 0.25 mm to about 2 mm,or about 0.25 mm to about 1.5 mm, or about 0.5 mm to about 5 mm, orabout 0.75 mm to about 5 mm, or about 1 mm to about 5 mm, or about 1.25mm to about 5 mm, or about 1.5 mm to about 5 mm, or about 2 mm to about5 mm, or about 2.5 mm to about 5 mm, or about 3 mm to about 5 mm, orabout 3.5 mm to about 5 mm, or about 0.5 mm to about 4 mm, or about 0.5mm to about 3.5 mm, or about 0.5 mm to about 3 mm, or about 0.75 mm toabout 2.5 mm, or about 1 mm to about 2.5 mm.

Base structure 12 has a thickness 22. In certain embodiments asotherwise described herein, the base structure has a thickness withinthe range of about 2 mm to about 50 mm. For example, in certain suchembodiments, the thickness of the base structure is within the range ofabout 2 mm to about 45 mm, or about 2 mm to about 40 mm, or about 2 mmto about 35 mm, or about 2 mm to about 30 mm, or about 2 mm to about 25mm, or about 2 mm to about 20 mm, or about 2 mm to about 17.5 mm, orabout 2 mm to about 15 mm, or about 2 mm to about 10 mm, or about 3 mmto about 50 mm, or about 4 mm to about 50 mm, or about 5 mm to about 50mm, or about 6 mm to about 50 mm, or about 7 mm to about 50 mm, or about8 mm to about 50 mm, or about 9 mm to about 50 mm, or about 10 mm toabout 50 mm, or about 12.5 mm to about 50 mm, or about 15 mm to about 50mm, or about 17.5 mm to about 50 mm, or about 20 mm to about 50 mm, orabout 3 mm to about 45 mm, or about 3 mm to about 40 mm, or about 4 mmto about 35 mm, or about 5 mm to about 30 mm, or about 5 mm to about 25mm, or about 5 mm to about 20 mm.

In certain embodiments as otherwise described herein, a width of theacoustic panel is within the range of about 12 to about 60 inches, e.g.,from 23 to 25 inches or from 46 to 50 inches, and a length of theacoustic panel is within the range of about 12 to about 144 inches,e.g., from 23 to 25 inches or from 46 to 50 inches.

The person of ordinary skill in the art will appreciate that basestructure 12 will have certain acoustic properties. In some aspects,base structure 12 has a characteristic noise reduction coefficient (NRC)of at least about 0.3. As used herein, a “noise reduction coefficient”or “NRC” describes the arithmetic average (e.g., rounded to the nearestmultiple of 0.05), of the absorption coefficients for a specific paneldetermined at 250 Hz, 500 Hz, 1000 Hz, and 2000 Hz. The person ofordinary skill in the art will appreciate that an “absorptioncoefficient” of a panel may be determined through standardized testingprocedures such as, for example, ASTM C423 (“Standard Test Method forSound Absorption and Sound Absorption Coefficients by the ReverberationRoom Method”). The person of ordinary skill in the art will furtherappreciate that, while intended to describe the fraction of randomlyincident sound power absorbed by a surface, an absorption coefficient isdefined operationally, and accordingly, highly absorptive panels canhave an absorption coefficient exceeding unity at one or morefrequencies.

In certain embodiments as otherwise described herein, the base structurehas independently a noise reduction coefficient of at least about 0.5.For example, in certain embodiments as otherwise described herein, thebase structure has independently a noise reduction coefficient of atleast about 0.55, e.g., at least about 0.6, or at least about 0.65, orat least about 0.7, or at least about 0.75, or at least about 0.8, or atleast about 0.85, or at least about 0.9, or at least about 0.95.

As described above, one aspect of the disclosure is a method forpreparing an acoustic panel comprising providing a base structure anddisposing directly against the outward major surface of the basestructure a sprayable mixture comprising a plurality of fibers, one ormore binders, and a dispersive medium. In certain embodiments asotherwise described herein, the fibers are formed of a polymer. Forexample, in certain such embodiments, the fibers are polyester,polypropylene, polyethylene, polyethylene terephthalate, polylacticacid, cellulose, polyvinyl chloride, or polyamide. In other embodimentsas otherwise described herein, the fibers are glass, e.g., borosilicateglass. Natural fibers, e.g., hemp or flax, can also be used.

In certain embodiments as otherwise described herein, the plurality offibers has an average length within the range of about 0.5 mm to about15 mm. For example, in certain such embodiments, the fibers have anaverage length within the range of about 0.5 mm to about 12.5 mm, orabout 0.5 mm to about 10 mm, or about 0.5 mm to about 9 mm, or about 0.5mm to about 8 mm, or about 0.5 mm to about 7 mm, or about 0.5 mm toabout 6 mm, or about 0.5 mm to about 5 mm, or about 0.75 mm to about 15mm, or about 1 mm to about 15 mm, or about 1.5 mm to about 15 mm, orabout 2 mm to about 15 mm, or about 3 mm to about 15 mm, or about 4 mmto about 15 mm, or about 5 mm to about 15 mm, or about 6 mm to about 15mm, or about 7 mm to about 15 mm, or about 8 mm to about 15 mm, or about9 mm to about 15 mm, or about 10 mm to about 15 mm, or about 0.75 mm toabout 12.5 mm, or about 1 mm to about 12.5 mm, or about 1.5 mm to about10 mm, or about 2 mm to about 10 mm, or about 3 mm to about 9 mm, orabout 3 mm to about 8 mm.

In certain embodiments as otherwise described herein, the plurality offibers has an average linear mass density within the range of about 0.1denier (“den,” or “D”) to about 25 D. For example, in certain suchembodiments, the fibers have an average linear mass density within therange of about 0.1 D to about 22.5 D, or about 0.1 D to about 20 D, orabout 0.1 D to about 17.5 D, or about 0.1 D to about 15 D, or about 0.1D to about 12.5 D, or about 0.1 D to about 10 D, or about 0.1 D to about9 D, or about 0.1 D to about 8 D, or about 0.1 D to about 7 D, or about0.25 D to about 25 D, or about 0.5 D to about 25 D, or about 1 D toabout 25 D, or about 1.5 D to about 25 D, or about 2 D to about 25 D, orabout 3 D to about 25 D, or about 4 D to about 25 D, or about 5 D toabout 25 D, or about 6 D to about 25 D, or about 7 D to about 25 D, orabout 8 D to about 25 D, or about 9 D to about 25 D, or about 10 D toabout 25 D, or about 12.5 D to about 25 D, or about 15 D to about 25 D,or about 17.5 D to about 25 D, or about 0.25 D to about 22.5 D, or about0.25 D to about 20 D, or about 0.5 D to about 17.5 D, or about 0.5 D toabout 15 D, or about 0.75 D to about 12.5 D, or about 1 D to about 10 D.

For example, in certain embodiments as otherwise described herein, thesprayable mixture disposed directly against the surface of the basestructure comprises a plurality of plastic (e.g., polyester) fibershaving an average length within the range of about 0.5 mm to about 15 mm(e.g., about 2 mm to about 10 mm) and an average linear mass densitywithin the range of about 0.1 D to about 25 D (e.g., about 0.5 D toabout 15 D).

The amount of the fibers in the sprayable mixture can vary, based inpart on the particular equipment and methods used to spray the mixture.In certain embodiments as otherwise described herein, the plurality offibers is present in the sprayable mixture in an amount within the rangeof about 0.1 wt. % to about 10 wt. %. For example, in certain suchembodiments, the fibers are present in the sprayable mixture in anamount within the range of about 0.1 wt. % to about 9 wt. %, or about0.1 wt. % to about 8 wt. %, or about or about 0.1 wt. % to about 7 wt.%, or about 0.1 wt. % to about 6 wt. %, or about 0.1 wt. % to about 5wt. %, or about 0.1 wt. % to about 4.5 wt. %, or about 0.1 wt. % toabout 4 wt. %, or about 0.1 wt. % to about 3.5 wt. %, or about 0.1 wt. %to about 3 wt. %, or about 0.25 wt. % to about 10 wt. %, or about 0.5wt. % to about 10 wt. %, or about 0.75 wt. % to about 10 wt. %, or about1 wt. % to about 10 wt. %, or about 1.5 wt. % to about 10 wt. %, orabout 2 wt. % to about 10 wt. %, or about 2.5 wt. % to about 10 wt. %,or about 3 wt. % to about 10 wt. %, or about 3.5 wt. % to about 10 wt.%, or about 4 wt. % to about 10 wt. %, or about 4.5 wt. % to about 10wt. %, or about 5 wt. % to about 10 wt. %, or about 6 wt. % to about 10wt. %, or about 7 wt. % to about 10 wt. %, or about 0.25 wt. % to about9 wt. %, or about 0.25 wt. % to about 8 wt. %, or about 0.5 wt. % toabout 7 wt. %, or about 0.5 wt. % to about 6 wt. %, or about 0.75 wt. %to about 5 wt. %, or about 0.75 wt. % to about 4.5 wt. %, or about 0.75wt. % to about 4 wt. %. In other embodiments, the fibers are present inthe sprayable mixture in an amount within the range of about 1 wt % toabout 30 wt %, e.g., about 1 wt % to about 25 wt %, or about 1 wt % toabout 20 wt %, or about 1 wt % to about 15 wt %, or about 1 wt % toabout 10 wt %, or about 5 wt % to about 30 wt %, or about 5 wt % toabout 25 wt %, or about 5 wt % to about 20 wt %, or about 5 wt % toabout 15 wt %, or about 10 wt % to about 30 wt %, or about 10 wt % toabout 25 wt %, or about 10 wt % to about 20 wt %. The person of ordinaryskill in the art will select, based on the present disclosure, an amountof fibers to provide a mixture that is sprayable using a desired type ofspraying equipment.

As described above, the sprayable mixture comprises one or more binders.In certain embodiments as otherwise described herein, the one or morebinders are selected from a rubber polymer and a plastic polymer. Incertain embodiments as otherwise described herein, the mixture comprisesa rubber polymer. For example, in certain such embodiments, the rubberpolymer is a styrene butadiene copolymer (e.g., a styrene butadienerubber or a styrene-butadiene-styrene block copolymer). In certainembodiments as otherwise described herein, the mixture comprises aplastic polymer. For example, in certain such embodiments, the plasticpolymer is polyacrylic or PVA. But other binders can be used. Forexample, in certain embodiments, the binder is a starch, e.g., amodified starch. A variety of other types of polymers can be used as thebinder, for example, polyurethanes, polyacrylates such as poly(methylmethacrylate), poly(ethyl acrylate), poly(butyl acrylate) andpoly(acrylic acid), styrene-acrylate copolymers,styrene-ethylene-butadiene-styrene block copolymer (SEBS), poly(vinylacetate) (PVAc), poly(ethylene-vinyl acetate) (EVA), ethylene-vinylchloride copolymers, polystyrene, poly vinyl acetate and poly vinylalcohol.

In certain embodiments as otherwise described herein, the one or morebinders are present in the sprayable mixture in a combined amount withinthe range of about 0.5 wt. % to about 30 wt. %. For example, in certainsuch embodiments, the one or more bindings are present in the sprayablemixture in a combined amount within the range of about 0.5 wt. % toabout 25 wt. %, or about 0.5 wt. % to about 20 wt. %, or about 0.5 wt. %to about 17.5 wt. %, or about 0.5 wt. % to about 15 wt. %, or about 0.5wt. % to about 12.5 wt. %, or about 0.5 wt. % to about 10 wt. %, orabout 0.5 wt. % to about 9 wt. %, or about 0.5 wt. % to about 8 wt. %,or about 0.5 wt. % to about 7 wt. %, or about 0.75 wt. % to about 30 wt.%, or about 1 wt. % to about 30 wt. %, or about 1.5 wt. % to about 30wt. %, or about 2 wt. % to about 30 wt. %, or about 3 wt. % to about 30wt. %, or about 4 wt. % to about 30 wt. %, or about 5 wt. % to about 30wt. %, or about 7.5 wt. % to about 30 wt. %, or about 10 wt. % to about30 wt. %, or about 12.5 wt. % to about 30 wt. %, or about 15 wt. % toabout 30 wt. %, or about 20 wt. % to about 30 wt. %, or about 0.75 wt. %to about 25 wt. %, or about 0.75 wt. % to about 20 wt. %, or about 1 wt.% to about 17.5 wt. %, or about 1 wt. % to about 15 wt. %, or about 1.5wt. % to about 12.5 wt. %, or about 1.5 wt. % to about 10 wt. %. Ofcourse, in some embodiments greater amounts of binder can be used. Incertain embodiments as otherwise described herein, the one or morebinders are present in the sprayable mixture in a combined amount withinthe range of about 1 wt % to about 50 wt %, e.g., about 1 wt % to about40 wt %, or about 5 wt % to about 50 wt %, or about 5 wt % to about 40wt %, or about 10 wt % to about 50 wt %, or about 10 wt % to about 40 wt%, or about 20 wt % to about 50 wt %, or about 20 wt % to about 40 wt %.

As described above, the sprayable mixture comprises a dispersive medium.In certain embodiments as otherwise described herein, the dispersivemedium includes water. Desirably, the dispersive medium is based chieflyon water as the liquid, to provide for inexpensive andenvironmentally-friendly use. In certain embodiments as otherwisedescribed herein, the total amount of water in the sprayable mixture isin the range of about 20 wt % to about 98 wt %, e.g., in the range ofabout 20 wt % to about 95 wt %, or about 20 wt % to about 90 wt %, orabout 20 wt % to about 80 wt %, or about 20 wt % to about 50 wt %, orabout 30 wt % to about 98 wt %, or about 30 wt % to about 95 wt %, orabout 30 wt % to about 90 wt %, or about 30 wt % to about 80 wt %, orabout 30 wt % to about 50 wt %, or about 40 wt % to about 98 wt %, orabout 40 wt % to about 95 wt %, or about 40 wt % to about 90 wt %, orabout 40 wt % to about 80 wt %, or about 40 wt % to about 60 wt %. Incertain embodiments as otherwise described herein, the the total amountof water in the sprayable mixture is in the range of about 50 wt % toabout 98 wt %, e.g., in range of about 50 wt % to about 95 wt %, orabout 50 wt % to about 90 wt %, or about 50 wt % to about 80 wt %, orabout 50 wt % to about 70 wt %, or about 60 wt % to about 98 wt %, orabout 60 wt % to about 95 wt %, or about 60 wt % to about 90 wt %, orabout 60 wt % to about 80 wt %. And in certain embodiments as otherwisedescribed herein, the total amount of water in the sprayable mixture isin the range of about 70 wt % to about 98 wt %, e.g., in the range ofabout 70 wt % to about 95 wt %, or about 70 wt % to about 90 wt %, orabout 70 wt % to about 80 wt %, or about 75 wt % to about 98, or about75 wt % to about 95 wt %, or about 75 wt % to about 90 wt %, or about 75wt % to about 85 wt %, or about 80 wt % to about 98 wt %, or about 80 wt% to about 95 wt %, or about 80 wt % to about 90 wt %, or about 85 wt %to about 98 wt %, or about 85 wt % to about 95 wt %, or about 90 wt % toabout 98 wt %.

In certain embodiments as otherwise described herein, the dispersivemedium comprises water and one or more of a viscosity modifier and adispersant. In certain embodiments as otherwise described herein, theone or more of a viscosity modifier and a dispersant are present in thedispersive medium in a combined amount within the range of about 0.1 wt.% to about 15 wt. %. For example, in certain such embodiments, the oneor more of a viscosity modifier and a dispersant are present in thedispersive medium in a combined about within the range of about 0.1 wt.% to about 12.5 wt. %, or about 0.1 wt. % to about 10 wt. %, or about0.1 wt. % to about 9 wt. %, or about 0.1 wt. % to about 8 wt. %, orabout 0.1 wt. % to about 7 wt. %, or about 0.1 wt. % to about 6 wt. %,or about 0.1 wt. % to about 5 wt. %, or about 0.25 wt. % to about 15 wt.%, or about 0.5 wt. % to about 15 wt. %, or about 0.75 wt. % to about 15wt. %, or about 1 wt. % to about 15 wt. %, or about 2 wt. % to about 15wt. %, or about 3 wt. % to about 15 wt. %, or about 4 wt. % to about 15wt. %, or about 5 wt. % to about 15 wt. %, or about 7.5 wt. % to about15 wt. %, or about 10 wt. % to about 15 wt. %, or about 0.25 wt. % toabout 12.5 wt. %, or about 0.25 wt. % to about 10 wt. %, or about 0.5wt. % to about 9 wt. %, or about 0.5 wt. % to about 8 wt. %. In certainembodiments as otherwise described herein, water is present in thedispersive medium in an amount within the range of about 85 wt. % toabout 99 wt. %. For example, in certain such embodiments, water ispresent in the dispersive medium in an amount within the range of about85 wt. % to about 97.5 wt. %, or about 85 wt. % to about 95 wt. %, orabout 85 wt. % to about 92.5 wt. %, or about 85 wt. % to about 90 wt. %,or about 87.5 wt. % to about 99 wt. %, or about 90 wt. % to about 99 wt.%, or about 92.5 wt. % to about 99 wt. %, or about 95 wt. % to about 99wt. %, or about 87.5 wt. % to about 95 wt. %, or about 90 wt. % to about97.5 wt. %, or about 92.5 wt. % to about 99 wt. %.

In certain embodiments as otherwise described herein, the dispersivemedium comprises a viscosity modifier. In certain such embodiments, theviscosity modifier is an anionic or cationic flocculant. In certainembodiments as otherwise described herein, the dispersive mediumcomprises a dispersant. In certain such embodiments, the dispersant isan alkyl amine. The person of ordinary skill in the art will appreciatethat a number of dispersants suitable for the dispersive medium, such asamphiphilic and/or ionic compounds, are known in the art.

In certain embodiments as otherwise described herein, the total amountof water, viscosity modifiers (e.g., an anionic or cation flocculant),and dispersants (e.g., an alkyl amine) is at least about 85 wt. % of thedispersive medium. For example, in certain embodiments as otherwisedescribed herein, the total amount of water, viscosity modifiers, anddispersants is at least about 87.5 wt. %, or at least about 90 wt. %, orat least about 92.5 wt. %, or at least about 95 wt. %, or at least about97.5 wt. %, or at least about 98 wt. %, or at least about 99 wt. %, orat least 99.5 wt. % of the dispersive medium.

In certain embodiments as otherwise described herein, the sprayablemixture further comprises a pigment. For example, in certain embodimentsas otherwise described herein, the sprayable mixture comprises titaniumdioxide, zinc oxide, or carbon black. Other common pigments suitable inthe sprayable mixture include, for example, transition metal and metaloxide pigments (e.g., iron oxides), anthraquinoids, quinacridone,phthalocyanines, ultramarines, nepheline syenite, barium sulfate,aluminum trihydrate, and magnesium oxide. In certain embodiments asotherwise described herein, the pigment is present in the sprayablemixture in an amount within the range of about 0.01 wt. % to about 10wt. % of the of the sprayable mixture. For example, in certain suchembodiments, the pigment is present in the sprayable mixture in anamount within the range of about 0.01 wt. % to about 9 wt. %, or about0.01 wt. % to about 8 wt. %, or about 0.01 wt. % to about 7 wt. %, orabout 0.01 wt. % to about 6 wt. %, or about 0.01 wt. % to about 5 wt. %,or about 0.01 wt. % to about 4.5 wt. %, or about 0.01 wt. % to about 4wt. %, or about 0.01 wt. % to about 3.5 wt. %, or about 0.01 wt. % toabout 3 wt. %, or about 0.01 wt. % to about 2.5 wt. %, or about 0.05 wt.% to about 10 wt. %, or about 0.1 wt. % to about 10 wt. %, or about 0.25wt. % to about 10 wt. %, or about 0.5 wt. % to about 10 wt. %, or about1 wt. % to about 10 wt. %, or about 1.5 wt. % to about 10 wt. %, orabout 2 wt. % to about 10 wt. %, or about 2.5 wt. % to about 10 wt. %,or about 3 wt. % to about 10 wt. %, or about 4 wt. % to about 10 wt. %,or about 5 wt. % to about 10 wt. %, or about 0.05 wt. % to about 9 wt.%, or about 0.1 wt. % to about 8 wt. %, or about 0.25 wt. % to about 7wt. %, or about 0.5 wt. % to about 6 wt. %, or about 1 wt. % to about 5wt. %. In certain embodiments as otherwise described herein, the fibersof the sprayable mixture (e.g., polyester fibers) comprise the pigmentof the sprayable mixture (e.g., titanium dioxide), for example, in anamount of about 0.1 wt. %, or 0.25 wt. %, or 0.5 wt. %, or 0.75 wt. %,or 1 wt. % of the fibers.

For example, in certain embodiments as otherwise described herein, thesprayable mixture comprises a plurality of polymer (e.g., polyester)fibers having an average length within the range of about 0.5 mm toabout 15 mm (e.g., about 0.5 mm to about 12.5 mm, or about 2 mm to about10 mm) and an average linear mass density within the range of about 0.1D to about 25 D (e.g., about 0.1 D to about 20 D, or about 0.5 D toabout 15 D), present in the sprayable mixture in an amount within therange of about 0.1 wt. % to about 25 wt. % (e.g., about 0.1 wt % toabout 10 wt %, or about 0.1 wt. % to about 8 wt. %, or about 0.5 wt. %to about 6 wt. %). In certain such embodiments, the sprayable mixturefurther comprises a polyacrylic or poly(vinyl alcohol) (PVA) binder,present in the sprayable mixture in an amount within the range of about0.5 wt. % to about 50 wt. % (e.g., about 0.5 wt % to about 30 wt %, orabout 0.5 wt. % to about 25 wt. %, or about 1 wt. % to about 15 wt. %).In certain such embodiments, the sprayable mixture further comprises atitanium dioxide pigment, present in the sprayable mixture in an amountwithin the range of about 0.01 wt. % to about 10 wt. % (e.g., about 0.01wt. % to about 8 wt. %, or about 0.5 wt. % to about 6 wt. %). In certainsuch embodiments, the sprayable mixture further comprises a dispersivemedium, present in the sprayable mixture in an amount within the rangeof about 80 wt. % to about 99 wt. %, comprising one or more of aviscosity modifier (e.g., an anionic or cationic flocculant) and adispersant (e.g., an alkyl amine), present in the dispersive medium in acombined about within the range of about 0.1 wt. % to about 15 wt. %,and water, present in the dispersive medium in an amount within therange of about 85 wt. % to about 99 wt. %.

In certain embodiments as otherwise described herein, the total amountof the binders, fibers, dispersive medium, and pigment is at least about85 wt. % of the sprayable mixture. For example, in certain embodimentsas otherwise described herein, the total amount of the binder, fibers,dispersive medium, and pigment is at least about 87.5 wt. %, or at leastabout 90 wt. %, or at least about 92.5 wt. %, or at least about 95 wt.%, or at least about 97.5 wt. %, or at least about 98 wt. %, or at leastabout 99 wt. %, or at least about 99.5 wt. % of the sprayable mixture.

As described above, one aspect of the disclosure is a method forpreparing an acoustic panel comprising disposing directly against theoutward major surface of a base structure a sprayable mixture, anddrying the disposed mixture to provide a facing layer. In certainembodiments as otherwise described herein, the method further comprisesapplying a paint to the outward major surface of the base structurebefore disposing the sprayable mixture directly against the outwardmajor surface. As used herein, the term “paint” describes curableliquids comprising a pigment (e.g., titanium dioxide), a binder (e.g.,acrylic polymer or styrene butadiene rubber), and a solvent (e.g.,water). The person of ordinary skill in the art will appreciate thatapplying a paint typically comprises brushing or spraying a thin coatingof paint onto a surface, and allowing the coating to dry and/or cure.

In certain embodiments as otherwise described herein, the coat weight ofthe disposed mixture before drying is within the range of about 25 g/m²to about 750 g/m². For example, in certain embodiments as otherwisedescribed herein, the coat weight of the disposed mixture before dryingis within the range of about 25 g/m² to about 650 g/m², or about 25 g/m²to about 550 g/m², or about 25 g/m to about 450 g/m², or about 25 g/m²to about 350 g/m², or about 25 g/m² to about 250 g/m², or about 25 g/m²to about 200 g/m², or about 25 g/m² to about 150 g/m², or about 50 g/m²to about 750 g/m², or about 75 g/m² to about 750 g/m², or about 100 g/m²to about 750 g/m², or about 150 g/m² to about 750 g/m², or about 200g/m² to about 750 g/m², or about 300 g/m² to about 750 g/m², or about400 g/m² to about 750 g/m², or about 50 g/m² to about 650 g/m², or about50 g/m² to about 550 g/m², or about 50 g/m² to about 450 g/m², or about50 g/m² to about 350 g/m², or about 75 g/m² to about 300 g/m². But incertain embodiments, e.g., when the fibers are glass fibers, higher coatweights can be used. For example, in certain embodiments as otherwisedescribed herein, the the coat weight of the disposed mixture beforedrying is within the range of about 25 g/m² to about 6000 g/m², e.g.,about 25 g/m² to about 4000 g/m², or about 25 g/m² to about 2500 g/m²,or about 25 g/m² to about 1500 g/m², or about 100 g/m² to about 6000g/m², or about 100 g/m² to about 4000 g/m², or about 100 g/m² to about2500 g/m², or about 100 g/m² to about 1500 g/m², or about 500 g/m² toabout 6000 g/m², or about 500 g/m² to about 4000 g/m², or about 500 g/m²to about 2500 g/m², or about 500 g/m² to about 1500 g/m², or about 1000g/m² to about 6000 g/m², or about 1000 g/m² to about 4000 g/m², or about1000 g/m² to about 2500 g/m².

The person of ordinary skill in the art will appreciate that thesprayable mixture can be disposed directly against the outward majorsurface of the base structure using any of a variety of spraying meansknown in the art. For example, in certain embodiments as otherwisedescribed herein, disposing the sprayable mixture comprises spraying thecomposition onto the outward major surface of the base structure with atexture sprayer or a hopper gun. The person of ordinary skill in the artwill appreciate that a variety of other spraying equipment can be used,and will select appropriate spraying equipment, based on the disclosureherein, in view of the spraying area, desired coating properties, andcomposition to be sprayed. The present inventors have determined that,advantageously, the mixture as otherwise described herein can remainsprayable (e.g., facilitating spray breakup, and avoiding clogging)while maintaining in suspension a relatively high loading of fibers.

In certain embodiments as otherwise described herein, the disposedmixture is dried at a temperature within the range of about 50° C. toabout 200° C. For example, in certain embodiments as otherwise describedherein, the disposed mixture is dried at a temperature within the rangeof about 50° C. to about 175° C., or about 50° C. to about 150° C., orabout 50° C. to about 125° C., or about 75° C. to about 200° C., orabout 100° C. to about 200° C., or about 125° C. to about 200° C., orabout 75° C. to about 175° C., or about 75° C. to about 150° C. Incertain embodiments as otherwise described herein, the method furthercomprises applying a paint to the exterior major surface of the facinglayer after drying the disposed mixture.

Another aspect of the disclosure is an acoustic panel. One embodiment ofthe disclosure is shown in schematic view in FIG. 1. The panel includesa base structure 12 having one or more edges 18, an outward majorsurface 14 having a total area, and an inward major surface 16 opposingthe outward major surface. The base structure has independently a noisereduction coefficient (NRC) of at least about 0.3. The panel furtherincludes a facing layer 24 directly disposed on the outward majorsurface of the base structure, the facing layer having an exterior majorsurface 26 opposing the outward major surface of the base structure. Thefacing layer 24 comprises a plurality of fibers and one or more binders.In certain embodiments, the acoustic panel is made by any method asdescribed herein.

In certain embodiments as otherwise described herein, the base structuredoes not comprise perforations. For example, in certain suchembodiments, the base structure has one or more physical properties(e.g., porosity) that provide desirable acoustic properties.

In other embodiments, the base structure comprises a plurality ofperforations extending from the outward major surface towards the inwardmajor surface, the plurality of perforations occupying an area of theoutward major surface. For example, base structure 12 comprises aplurality of perforations 20 (shown in part in FIG. 1). In certainembodiments as otherwise described herein, the plurality of perforationsoccupies an area of the outward major surface that is within the rangeof about 0.1% to about 10% of the total area of the outward majorsurface of base structure 12.

The person of ordinary skill in the art will appreciate that facinglayer 24, comprising a plurality of fibers and one or more binders, willhave certain optical properties. In some aspects, facing layer 24 canhave a characteristic light scattering percentage. In certainembodiments as otherwise described herein, the facing layer issubstantially scattering for light in the wavelength range of 400 nm to700 nm. For example, in certain such embodiments, the facing layer has alight scattering percentage of at least about 50%, or at least about55%, or at least about 60%, or at least about 65%, or at least about70%, or at least about 75%, or at least about 80%, or at least about85%, or at least about 90%, or at least about 95%, for a wavelengthregion of 400 nm to 700 nm.

The person of ordinary skill in the art will further appreciate thatfacing layer 24 will have, independently of the base structure, certainacoustic properties. In some aspects, facing layer 24 can have acharacteristic sound absorption coefficient. In certain embodiments asotherwise described herein, the facing layer is substantiallytransparent to sound. For example, in certain embodiments as otherwisedescribed herein, the facing layer has an absorption coefficient of lessthan 0.5 for acoustic frequencies in the range of 100 Hz to 10,000 Hz.In certain such embodiments, the facing layer has an absorptioncoefficient of less than 0.45, or less than 0.4, or less than 0.35, orless than 0.3, or less than 0.25 for acoustic frequencies in the rangeof 100 Hz to 10,000 Hz. In another example, in certain embodiments asotherwise described herein, the facing layer and the base structure eachindependently have an air resistivity, and the air resistivity of thefacing layer is equal to or less than the air resistivity of the basestructure. In certain such embodiments, the air resistivity of the basestructure is at least 25%, or at least 50%, or at least 75%, or at leastabout 100% greater than the air resistivity of the facing layer. In someembodiments, the air resistivity of the facing layer is in a range ofabout 1 to about 2000 kPa·s/m², or about 10 to about 1000 kPa·s/m², orabout 100 to about 500 kPa·s/m².

The person of ordinary skill in the art will further appreciate thatpanel 10, comprising base structure 12 and facing layer 24, will havecertain acoustic properties. In some aspects, panel 10 can have acharacteristic noise reduction coefficient. In certain embodiments asotherwise described herein, the acoustic panel has a noise reductioncoefficient of at least about 0.3, e.g., at least about 0.35, or atleast about 0.4, or at least about 0.45. In certain embodiments asotherwise described herein, the acoustic panel has a noise reductioncoefficient of at least about 0.5. For example, in certain embodimentsas otherwise described herein, the acoustic panel has a noise reductioncoefficient of at least about 0.55, or at least about 0.6, or at leastabout 0.65, or at least about 0.7, or at least about 0.75, or at leastabout 0.8, or at least about 0.85, or at least about 0.9, or at leastabout 0.95. In certain embodiments as otherwise described herein, thenoise reduction coefficient of the acoustic panel is at least about 70%of the noise reduction coefficient of the base structure independently.For example, in certain such embodiments, the noise reductioncoefficient of the acoustic panel is at least about 75%, or at leastabout 80%, or at least about 85%, or at least about 90%, or at leastabout 95% of the noise reduction coefficient of the base structureindependently.

Facing layer 24 has a thickness 28. In certain embodiments as otherwisedescribed herein, the thickness of the facing layer is within the rangeof about 0.25 mm to about 20 mm. For example, in certain suchembodiments, the thickness of the facing layer is within the range ofabout 0.25 mm to about 17.5 mm, or about 0.25 mm to about 15 mm, orabout 0.25 mm to about 12.5 mm, or about 0.25 mm to about 10 mm, orabout 0.25 mm to about 9 mm, or about 0.25 mm to about 8 mm, or about0.25 mm to about 7 mm, or about 0.25 mm to about 6 mm, or about 0.25 mmto about 5 mm, or about 0.5 mm to about 20 mm, or about 0.75 mm to about20 mm, or about 1 mm to about 20 mm, or about 1.5 mm to about 20 mm, orabout 2 mm to about 20 mm, or about 3 mm to about 20 mm, or about 4 mmto about 20 mm, or about 5 mm to about 20 mm, or about 7.5 mm to about20 mm, or about 10 mm to about 20 mm, or about 0.5 mm to about 15 mm, orabout 0.5 mm to about 10 mm, or about 0.75 mm to about 9 mm, or about0.75 mm to about 8 mm, or about 1 mm to about 7 mm, or about 1 mm toabout 6 mm, or about 1 mm to about 5 mm.

In certain embodiments as otherwise described herein, the facing layercomprises fibers (e.g., polyester fibers) in an amount within the rangeof about 10 wt. % to about 50 wt. %. For example, in certain suchembodiments, the facing layer comprises fibers in an amount within therange of about 10 wt. % to about 45 wt. %, or about 10 wt. % to about 40wt. %, or about 10 wt. % to about 35 wt. %, or about 10 wt. % to about30 wt. %, or about 10 wt. % to about 25 wt. %, or about 15 wt. % toabout 50 wt. %, or about 20 wt. % to about 50 wt. %, or about 25 wt. %to about 50 wt. %, or about 30 wt. % to about 50 wt. %, or about 35 wt.% to about 50 wt. %, or about 15 wt. % to about 45 wt. %, or about 15wt. % to about 40 wt. %, or about 20 wt. % to about 35 wt. %.

In certain embodiments as otherwise described herein, the facing layercomprises binder (e.g., a rubber polymer or a plastic polymer) andpigment (e.g., titanium dioxide) in a combined amount within the rangeof about 40 wt. % to about 90 wt. %. For example, in certain suchembodiments, the facing layer comprises binder and pigment in a combinedamount within the range of about 40 wt. % to about 85 wt. %, or about 40wt. % to about 80 wt. %, or about 40 wt. % to about 75 wt. %, or about40 wt. % to about 70 wt. %, or about 40 wt. % to about 65 wt. %, orabout 40 wt. % to about 60 wt. %, or about 40 wt. % to about 55 wt. %,or about 45 wt. % to about 90 wt. %, or about 50 wt. % to about 90 wt.%, or about 55 wt. % to about 90 wt. %, or about 60 wt. % to about 90wt. %, or about 65 wt. % to about 90 wt. %, or about 70 wt. % to about90 wt. %, or about 75 wt. % to about 90 wt. %, or about 50 wt. % toabout 85 wt. %, or about 55 wt. % to about 85 wt. %, or about 60 wt. %to about 80 wt. %, or about 65 wt. % to about 80 wt. %.

In certain embodiments as otherwise described herein, the outward majorsurface of the base structure comprises a localized paint (e.g.,provided by applying a paint to the outward major surface of the basestructure before disposing the sprayable mixture directly against theoutward major surface). In certain such embodiments, the color of theoutward major surface is white.

In certain embodiments as otherwise described herein, the outward majorsurface of the base structure comprises a localized adhesive. However,the present inventors have determined that the acoustic panels asotherwise described herein can be prepared according to methods asotherwise described herein, without the use of a localized adhesive,which can be costly and can negatively affect the acoustic performanceof the panel. Accordingly, in certain embodiments, an adhesive is notlocalized on the outward major surface of the base structure of theacoustic panel as otherwise described herein. In certain suchembodiments, neither is a paint localized on the outward major surfaceof the base structure.

In certain embodiments as otherwise described herein, the exterior majorsurface of the facing layer comprises a localized paint (e.g., providedby applying a paint to the exterior major surface of the facing layerafter drying the sprayable mixture disposed directly against the basestructure). In certain such embodiments, the color of the exterior majorsurface is white.

In certain embodiments as otherwise described herein, the panel isresistant to sagging.

Notably, the methods described herein can be performed to provideacoustic panels in a system that forms an architectural surface.Accordingly, another aspect of the disclosure is a panel systemcomprising a plurality of support beams arranged in a support grid so asto form a plurality of grid openings in the support grid, and aplurality of panels respectively aligned with the openings of thesupport grid, where at least one of the panels is an acoustic panel asdescribed herein, or an acoustic panel prepared according to a methoddescribed herein. In certain embodiments, each panel of the plurality isoriented such that the exterior major surface of the facing layer isfacing an interior space adjacent to the support grid. The person ofordinary skill in the art will appreciate that the perforations of thebase structures of each panel will, in such an arrangement, beadvantageously obscured by the facing layer while still being accessibleto air and sound waves.

EXAMPLES

The Examples that follow are illustrative of specific embodiments of theinvention, and various uses thereof. They are set forth for explanatorypurposes only, and are not to be taken as limiting the invention.

Example 1. Sprayable Mixture Preparation

Formulation 1:

A 2.4% solution of Nalco 7763 viscosity modifier in water was mixedgently at 50° C. for 1 hr. 17.69 g of the 2.4% viscosity modifiersolution was added to 71.2 g of DI water, followed by 0.35 g of Nalco8493 dispersant. While mixing under high shear, 1.86 g of polyesterfibers (6-mm average length, 1.5 D average linear mass density, 0.31%TiO₂) were slowly added. Then 8.85 g of a 52% solution of a mixture of astyrenated polyacrylic binder and titanium dioxide in water was addedwhile mixing under low shear.

Formulation 2:

A 2.4% solution of Nalco 7763 viscosity modifier in water was mixedgently at 50° C. for 1 hr. 17.46 g of the 2.4% viscosity modifiersolution was added to 73.37 g of DI water, followed by 0.17 g of Nalco8493 dispersant. Then 5.71 g of Wacker Vinnol 4530 (an aqueous,terpolymer dispersion based on the monomers vinyl chloride, ethylene,and a third monomer imparting amide functionality) was added whilemixing under low shear. While mixing under high shear, 3.56 g ofpolyester fibers (6-mm average length, 1.5 D average linear massdensity, 0.31% TiO₂) were slowly added.

Formulation 3:

A 2.4% solution of Nalco 7763 viscosity modifier in water was mixedgently at 50° C. for 1 hr. 17.46 g of the 2.4% viscosity modifiersolution was added to 73.37 g of DI water, followed by 0.17 g of Nalco8493 dispersant. Then 5.71 g of Celanese Dur-O-Cote FF (Anon-crosslinking, surfactant protected, vinyl acetate emulsion) wasadded while mixing under low shear. While mixing under high shear, 3.56g of polyester fibers (6-mm average length, 1.5 D average linear massdensity, 0.31% TiO₂) were slowly added.

Formulation 4:

A 2.4% solution of Nalco 7763 viscosity modifier in water was mixedgently at 50° C. for 1 hr. 9.23 g of the 2.4% viscosity modifiersolution was added to 78.83 g of DI water, followed by 0.19 g of Nalco8493 dispersant. Then 5.71 g of Wacker Vinnol 4530 (A non-crosslinking,surfactant protected, vinyl acetate emulsion) was added while mixingunder low shear. While mixing under high shear, 5.69 g of polyesterfibers (6-mm average length, 1.5 D average linear mass density, 0.31%TiO₂) were slowly added.

Example 2. Panel Preparation

The mixture of Formulation 1 was sprayed with a hopper gun onto amineral wool base structure having an NRC of about 0.3 having a 3% totalcoverage of 1.4-mm perforations, and then dried at about 110° C. forabout 5 minutes to provide a facing layer having a thickness of 1.2-5.6mm. After drying, the NRC of the was about 0.3.

Example 3. Panel Preparation

White paint was applied to a mineral wool base structure having an NRCof about 0.3 having a 3% total coverage of 1.4-mm perforations toprovide a paint layer having a thickness of 1-3 mm. After drying thepaint, the mixture of Formulation 1 was sprayed with a hopper gun ontothe painted mineral wool base structure, and then dried at about 110° C.for about 5 minutes to provide a facing layer having a thickness of1.2-5.6 mm.

After drying, white paint was applied to the facing layer of the panelto provide a layer having a thickness of 1-3 mm, and dried. FIG. 2 showsthe results after drying of facing layers having paint coatings of about30 g/m² (FIG. 2A), about 100 g/m² (FIG. 2B), and about 175 g/m² (FIG.2C). After drying, the NRC of the panel was about 0.3.

The results show that the mixture could be effectively sprayed onto to aperforated base structure, and that the resulting facing layer obscuredthe perforated structure without detrimentally affecting the mechanicalor acoustical properties of the panel.

Example 4. Sprayability of Formulations

Formulation 2 was supplied from a pressure pot under about 60 psi to aGraco Texture Spray Gun. The formulation was sprayed under thisconfiguration with good atomization and no jamming.

Formulation 2 was supplied from a pressure pot under about 60 psi to aGraco brand external mix spray gun. The formulation jammed under thisconfiguration.

Formulation 2 was supplied from a pressure pot under about 60 psi to aGraco brand high volume low pressure (HVLP) spray gun. The formulationjammed under this configuration.

Formulation 2 was supplied from a peristaltic pump to a Graco TextureSpray Gun. The formulation sprayed initially, but then jammed under thisconfiguration.

Formulation 2 was circulated through a Binks Maple 15 piston pump. Theformulation jammed under this configuration.

Formulation 2 was circulated through a Dayton 5UXL7 flexible impellerpump. The formulation flowed reliably with no jamming under thisconfiguration.

Formulation 3 was circulated through a Moyno 34459 progressive cavitypump. The formulation flowed reliably with no jamming under thisconfiguration.

A 5-gallon reservoir of Formulation 3 was connected to a Moyno 34459progressive cavity pump with flexible tubing. The pump was connected toa Binks Model 21M automatic spray gun with flexible tubing. The outputflow from the pump was split between supplying the spray gun and beingdiverted into a recirculation loop which fed back into the formulationreservoir. The spray gun was supplied with compressed air at 45 psi toopen the cylinder, and 50 psi atomization air. The formulation wassprayed under this configuration with good atomization and no jamming.

Formulation 4 was supplied from a pressure pot under about 60 psi to aGraco Texture Spray Gun. The formulation was not continuously sprayableunder this configuration.

Additional aspects of the disclosure are provided by the followingenumerated embodiments, which can be combined in any number and in anycombination that is not logically or technically inconsistent.

Embodiment 1

A method for preparing an acoustic panel comprising

-   -   providing a base structure having one or more edges, an outward        major surface having a total area, and an inward major surface        opposing the outward major surface, the base structure having        independently a noise reduction coefficient (NRC) of at least        about 0.3; and    -   disposing directly against the outward major surface of the base        structure a sprayable mixture comprising        -   a plurality of fibers;        -   one or more binders; and        -   a dispersive medium; and    -   drying the disposed mixture to provide a facing layer disposed        on the outward major surface of the base structure, the facing        layer having an exterior major surface opposing the outward        major surface of the base structure.

Embodiment 2

A method according to embodiment 1, wherein the base structure comprises

-   -   one or more of mineral wool, fiberglass, gypsum, wood fiber,        paper, cellulose fiber, wet-laid felt, and foam;    -   one or more fillers; and    -   one or more binders;    -   present in the base structure in a combined amount of at least        about 85 wt. %, or at least about 95 wt. %, or at least about        97.5 wt. %, or at least about 99 wt. %.

Embodiment 3

A method according to embodiment 2, wherein the base structure comprisesmineral wool.

Embodiment 4

A method according to any of embodiments 1-3, wherein the base structurecomprises a plurality of perforations extending from the outward majorsurface towards the inward major surface, the plurality of perforationsoccupying an area of the outward major surface within the range of about0.1% to about 10% of the total area of the outward major surface

Embodiment 5

A method according to embodiment 4, wherein the perforations occupy anarea of the outward major surface within the range of about 0.5% toabout 10%, e.g., about 0.5% to about 8%, or about 1% to about 6%.

Embodiment 6

A method according to embodiment 4 or 5, wherein the perforations areround, and the average diameter of the perforations is within the rangeof about 0.25 mm to about 5 mm, e.g., about 0.25 mm to about 4 mm, orabout 0.5 mm to about 3 mm.

Embodiment 7

A method according to any of embodiments 4-6, wherein the average depthof the perforations is at least about 3 mm, e.g., at least about 4 mm,or at least about 5 mm.

Embodiment 8

A method according to any of embodiments 1-7, wherein the base structurehas a thickness within the range of about 2 mm to about 50 mm, e.g.,about 2 mm to about 35 mm, or about 5 mm to about 25 mm.

Embodiment 9

A method according to any of embodiments 1-8, wherein the base structurehas independently a noise reduction coefficient (NRC) of at least about0.5, e.g., at least about 0.6, or at least about 0.7, or at least about0.8.

Embodiment 10

A method according to any of embodiments 1-9, wherein the fibers areplastic, e.g., polyester, polypropylene, polyethylene, polyethyleneterephthalate, polylactic acid, cellulose, polyvinyl chloride, orpolyamide.

Embodiment 11

A method according to any of embodiments 1-9, wherein the fibers areglass, e.g., borosilicate glass, or natural fibers, e.g., flax or hemp.

Embodiment 12

A method according to any of embodiments 1-11, wherein the fibers havean average length within the range of about 0.5 mm to about 12.5 mm,e.g., about 0.5 mm to about 10 mm, or about 0.5 mm to about 9 mm, orabout 0.5 mm to about 8 mm, or about 0.5 mm to about 7 mm, or about 0.5mm to about 6 mm, or about 0.5 mm to about 5 mm, or about 0.75 mm toabout 15 mm, or about 1 mm to about 15 mm, or about 1.5 mm to about 15mm, or about 2 mm to about 15 mm, or about 3 mm to about 15 mm, or about4 mm to about 15 mm, or about 5 mm to about 15 mm, or about 6 mm toabout 15 mm, or about 7 mm to about 15 mm, or about 8 mm to about 15 mm,or about 9 mm to about 15 mm, or about 10 mm to about 15 mm, or about0.75 mm to about 12.5 mm, or about 1 mm to about 12.5 mm, or about 1.5mm to about 10 mm, or about 2 mm to about 10 mm, or about 3 mm to about9 mm, or about 3 mm to about 8 mm.

Embodiment 13

A method according to any of embodiments 1-12, wherein the fibers havean average linear mass density within the range of about 0.1 denier (D)to about 25 D, e.g., 0.1 D to about 22.5 D, or about 0.1 D to about 20D, or about 0.1 D to about 17.5 D, or about 0.1 D to about 15 D, orabout 0.1 D to about 12.5 D, or about 0.1 D to about 10 D, or about 0.1D to about 9 D, or about 0.1 D to about 8 D, or about 0.1 D to about 7D, or about 0.25 D to about 25 D, or about 0.5 D to about 25 D, or about1 D to about 25 D, or about 1.5 D to about 25 D, or about 2 D to about25 D, or about 3 D to about 25 D, or about 4 D to about 25 D, or about 5D to about 25 D, or about 6 D to about 25 D, or about 7 D to about 25 D,or about 8 D to about 25 D, or about 9 D to about 25 D, or about 10 D toabout 25 D, or about 12.5 D to about 25 D, or about 15 D to about 25 D,or about 17.5 D to about 25 D, or about 0.25 D to about 22.5 D, or about0.25 D to about 20 D, or about 0.5 D to about 17.5 D, or about 0.5 D toabout 15 D, or about 0.75 D to about 12.5 D, or about 1 D to about 10 D.

Embodiment 14

A method according to any of embodiments 1-13, wherein

-   -   the fibers are polymeric (e.g., polyester);    -   the fibers have an average length within the range of about 0.5        mm to about 15 mm (e.g., about 2 mm to about 10 mm); and    -   the fibers have an average linear mass density within the range        of about 0.1 D to about 25 D (e.g., about 0.5 D to about 15 D).

Embodiment 15

A method according to any of embodiments 1-14, wherein the fibers arepresent in the sprayable mixture in an amount within the range of about0.1 wt. % to about 10 wt. %, e.g., about 0.1 wt. % to about 8 wt. %, orabout 0.5 wt. % to about 6 wt. %.

Embodiment 16

A method according to any of embodiments 1-14, wherein the fibers arepresent in the sprayable mixture in an amount within the range of about1 wt % to about 30 wt %, e.g., about 1 wt % to about 25 wt %, or about 1wt % to about 20 wt %, or about 1 wt % to about 15 wt %, or about 1 wt %to about 10 wt %, or about 5 wt % to about 30 wt %, or about 5 wt % toabout 25 wt %, or about 5 wt % to about 20 wt %, or about 5 wt % toabout 15 wt %, or about 10 wt % to about 30 wt %, or about 10 wt % toabout 25 wt %, or about 10 wt % to about 20 wt %.

Embodiment 17

A method according to any of embodiments 1-16, wherein the one or morebinders of the sprayable mixture are selected from a rubber polymer anda plastic polymer.

Embodiment 18

A method according to embodiment 17, wherein the rubber polymer is astyrene butadiene copolymer.

Embodiment 19

A method according to embodiment 17, wherein the plastic polymer is apolyacrylic or poly(vinyl alcohol) (PVA).

Embodiment 20

A method according to any of embodiments 1-16, wherein the one or morebinders of the sprayable mixture includes a starch, e.g., a modifiedstarch.

Embodiment 21

A method according to any of embodiments 1-16, wherein the one or morebinders of the sprayable mixture includes a polymeric binder, e.g.,selected from polyurethanes, polyacrylates such as poly(methylmethacrylate), poly(ethyl acrylate), poly(butyl acrylate) andpoly(acrylic acid), styrene-acrylate copolymers,styrene-ethylene-butadiene-styrene block copolymer (SEBS), poly(vinylacetate) (PVAc), poly(ethylene-vinyl acetate) (EVA), ethylene-vinylchloride copolymers, polystyrene, poly vinyl acetate and poly vinylalcohol.

Embodiment 22

A method according to any of embodiments 1-21, wherein the one or morebinders are present in the sprayable mixture in a combined amount withinthe range of about 0.5 wt. % to about 30 wt. %, e.g., about 0.5 wt. % toabout 25 wt. %, or about 0.5 wt. % to about 20 wt. %, or about 0.5 wt. %to about 17.5 wt. %, or about 0.5 wt. % to about 15 wt. %, or about 0.5wt. % to about 12.5 wt. %, or about 0.5 wt. % to about 10 wt. %, orabout 0.5 wt. % to about 9 wt. %, or about 0.5 wt. % to about 8 wt. %,or about 0.5 wt. % to about 7 wt. %, or about 0.75 wt. % to about 30 wt.%, or about 1 wt. % to about 30 wt. %, or about 1.5 wt. % to about 30wt. %, or about 2 wt. % to about 30 wt. %, or about 3 wt. % to about 30wt. %, or about 4 wt. % to about 30 wt. %, or about 5 wt. % to about 30wt. %, or about 7.5 wt. % to about 30 wt. %, or about 10 wt. % to about30 wt. %, or about 12.5 wt. % to about 30 wt. %, or about 15 wt. % toabout 30 wt. %, or about 20 wt. % to about 30 wt. %, or about 0.75 wt. %to about 25 wt. %, or about 0.75 wt. % to about 20 wt. %, or about 1 wt.% to about 17.5 wt. %, or about 1 wt. % to about 15 wt. %, or about 1.5wt. % to about 12.5 wt. %, or about 1.5 wt. % to about 10 wt. %.

Embodiment 23

A method according to any of embodiments 1-21, wherein the one or morebinders are present in the sprayable mixture in a combined amount withinthe range of about 1 wt % to about 50 wt %, e.g., about 1 wt % to about40 wt %, or about 5 wt % to about 50 wt %, or about 5 wt % to about 40wt %, or about 10 wt % to about 50 wt %, or about 10 wt % to about 40 wt%, or about 20 wt % to about 50 wt %, or about 20 wt % to about 40 wt %.

Embodiment 24

A method according to any of embodiments 1-23, wherein the dispersivemedium comprises

-   -   one or more of a viscosity modifier and a dispersant, present in        the dispersive medium in a combined amount within the range of        about 0.1 wt. % to about 15 wt. %; and    -   water, present in the dispersive medium in an amount within the        range of about 85 wt. % to about 99 wt. %.

Embodiment 25

A method according to embodiment 24, wherein the viscosity modifier isan anionic or cationic flocculant.

Embodiment 26

A method according to embodiment 24 or embodiment 25, wherein thedispersant is an alkyl amine.

Embodiment 27

A method according to any of embodiments 24-26, wherein the total amountof water, viscosity modifiers, and dispersants is at least about 85 wt.% (e.g., at least about 90 wt. %, or at least about 95 wt. %, or atleast about 97.5 wt. %, or at least about 99 wt. %) of the dispersivemedium.

Embodiment 28

A method according to any of embodiments 1-27, wherein the total amountof water in the sprayable mixture is in the range of about 20 wt % toabout 98 wt %, e.g., in the range of about 20 wt % to about 95 wt %, orabout 20 wt % to about 90 wt %, or about 20 wt % to about 80 wt %, orabout 20 wt % to about 50 wt %, or about 30 wt % to about 98 wt %, orabout 30 wt % to about 95 wt %, or about 30 wt % to about 90 wt %, orabout 30 wt % to about 80 wt %, or about 30 wt % to about 50 wt %, orabout 40 wt % to about 98 wt %, or about 40 wt % to about 95 wt %, orabout 40 wt % to about 90 wt %, or about 40 wt % to about 80 wt %, orabout 40 wt % to about 60 wt %.

Embodiment 29

A method according to any of embodiments 1-27, wherein the total amountof water in the sprayable mixture is in the range of about 50 wt % toabout 98 wt %, e.g., in range of about 50 wt % to about 95 wt %, orabout 50 wt % to about 90 wt %, or about 50 wt % to about 80 wt %, orabout 50 wt % to about 70 wt %, or about 60 wt % to about 98 wt %, orabout 60 wt % to about 95 wt %, or about 60 wt % to about 90 wt %, orabout 60 wt % to about 80 wt %.

Embodiment 30

A method according to any of embodiments 1-27, wherein the total amountof water in the sprayable mixture is in the range of about 70 wt % toabout 98 wt %, e.g., in the range of about 70 wt % to about 95 wt %, orabout 70 wt % to about 90 wt %, or about 70 wt % to about 80 wt %, orabout 75 wt % to about 98, or about 75 wt % to about 95 wt %, or about75 wt % to about 90 wt %, or about 75 wt % to about 85 wt %, or about 80wt % to about 98 wt %, or about 80 wt % to about 95 wt %, or about 80 wt% to about 90 wt %, or about 85 wt % to about 98 wt %, or about 85 wt %to about 95 wt %, or about 90 wt % to about 98 wt %.

Embodiment 31

A method according to any of embodiments 1-30, wherein the sprayablemixture further comprises a pigment.

Embodiment 32

A method according to embodiment 31, wherein the pigment is selectedfrom titanium dioxide, zinc oxide, and carbon black.

Embodiment 33

A method according to embodiment 31 or 32, wherein the pigment ispresent in the sprayable mixture in an amount within the range of about0.01 wt. % to about 10 wt. %, e.g., about 0.01 wt. % to about 8 wt. %,or about 0.1 wt. % to about 6 wt. %.

Embodiment 34

A method according to any of embodiments 1-33, wherein the sprayablemixture comprises

-   -   a plurality of fibers (e.g., polyester fibers) having an average        length within the range of about 0.5 mm to about 15 mm and an        average linear mass density within the range of about 0.1 D to        about 25 D, present in the sprayable mixture in an amount within        the range of about 0.1 wt. % to about 10 wt. %;    -   a binder (e.g., a polyacrylic binder or a PVA binder), present        in the sprayable mixture in an amount within the range of about        0.5 wt. % to about 30 wt. %;    -   a dispersive medium, present in the sprayable mixture in an        amount within the range of about 80 wt. % to about 99 wt. %,        comprising        -   one or more of a viscosity modifier and a dispersant,            present in the dispersive medium in a combined amount within            the range of about 0.1 wt. % to about 15 wt. %; and        -   water, present in the dispersive medium in an amount within            the range of about 85 wt. % to about 99 wt. %.

Embodiment 35

A method according to any of embodiments 1-33, wherein the sprayablemixture comprises

-   -   a plurality of fibers (e.g., polyester fibers) having an average        length within the range of about 0.5 mm to about 15 mm and an        average linear mass density within the range of about 0.1 D to        about 25 D, present in the sprayable mixture in an amount within        the range of about 0.1 wt. % to about 25 wt. %;    -   a polyacrylic binder or a PVA binder, present in the sprayable        mixture in an    -   amount within the range of about 0.5 wt. % to about 50 wt. %;    -   a dispersive medium, present in the sprayable mixture in an        amount within the range of about 80 wt. % to about 99 wt. %,        comprising        -   one or more of a viscosity modifier and a dispersant,            present in the dispersive medium in a combined amount within            the range of about 0.1 wt. % to about 15 wt. %; and        -   water, present in the dispersive medium in an amount within            the range of about 85 wt. % to about 99 wt. %.

Embodiment 36

A method according to embodiment 34 or embodiment 35, wherein thesprayable mixture further comprises a titanium dioxide pigment, presentin the sprayable mixture in an amount within the range of about 0.01 wt.% to about 10 wt. %.

Embodiment 37

A method according to any of embodiments 1-36, wherein the total amountof the binder, fibers, dispersive medium, and pigment is at least about85 wt. % (e.g., at least about 90 wt. %, or at least about 95 wt. %, orat least about 97.5 wt. %, or at least about 99 wt. %) of the sprayablemixture.

Embodiment 38

A method according to any of embodiments 1-37, further comprisingapplying a paint to the outward major surface of the base structurebefore disposing the sprayable mixture directly against the outwardmajor surface.

Embodiment 39

A method according to any of embodiments 1-38, wherein the coat weightof the disposed mixture before drying is within the range of about 25g/m² to about 750 g/m², e.g., 25 g/m² to about 650 g/m², or about 25g/m² to about 550 g/m², or about 25 g/m to about 450 g/m², or about 25g/m² to about 350 g/m², or about 25 g/m² to about 250 g/m², or about 25g/m² to about 200 g/m², or about 25 g/m² to about 150 g/m², or about 50g/m² to about 750 g/m², or about 75 g/m² to about 750 g/m², or about 100g/m² to about 750 g/m², or about 150 g/m² to about 750 g/m², or about200 g/m² to about 750 g/m², or about 300 g/m² to about 750 g/m², orabout 400 g/m² to about 750 g/m², or about 50 g/m² to about 650 g/m², orabout 50 g/m² to about 550 g/m², or about 50 g/m² to about 450 g/m², orabout 50 g/m² to about 350 g/m², or about 75 g/m² to about 300 g/m².

Embodiment 40

A method according to any of embodiments 1-38, wherein the coat weightof the disposed mixture before drying is within the range of about 25g/m² to about 6000 g/m², e.g., about 25 g/m² to about 4000 g/m², orabout 25 g/m² to about 2500 g/m², or about 25 g/m² to about 1500 g/m²,or about 100 g/m² to about 6000 g/m², or about 100 g/m² to about 4000g/m², or about 100 g/m² to about 2500 g/m², or about 100 g/m² to about1500 g/m², or about 500 g/m² to about 6000 g/m², or about 500 g/m² toabout 4000 g/m², or about 500 g/m² to about 2500 g/m², or about 500 g/m²to about 1500 g/m², or about 1000 g/m² to about 6000 g/m², or about 1000g/m² to about 4000 g/m², or about 1000 g/m² to about 2500 g/m².

Embodiment 41

A method according to any of embodiments 1-40, wherein disposing thesprayable composition comprises spraying the composition onto theoutward major surface of the base structure with a texture sprayer or ahopper gun.

Embodiment 42

A method according to any of embodiments 1-41, wherein the dryingtemperature is within the range of about 50° C. to about 200° C., e.g.,about 75° C. to about 150° C.

Embodiment 43

A method according to any of embodiments 1-42, further comprisingapplying a paint to the exterior major surface of the facing layer afterdrying the disposed mixture.

Embodiment 44

An acoustic panel, made by a method of any of embodiments 1-43.

Embodiment 45

An acoustic panel (e.g., made by a method of any of embodiments 1-43)comprising

-   -   a base structure having one or more edges, an outward major        surface having a total area, and an inward major surface        opposing the outward major surface, the base structure having        independently an NRC of at least about 0.3; and    -   a facing layer directly disposed on the outward major surface of        the base structure, the facing layer comprising a plurality of        fibers and one or more binders, the facing layer having an        exterior major surface opposing the outward major surface of the        base structure.

Embodiment 46

A panel according to embodiment 45, wherein the base structure comprisesa plurality of perforations extending from the outward major surfacetowards the inward major surface, the plurality of perforationsoccupying an area of the outward major surface within the range of about0.1% to about 10% of the total area of the outward major surface,

Embodiment 47

A panel according to embodiment 45 or 46, wherein the fibers arepolymeric, e.g., polyester, polypropylene, polyethylene, polyethyleneterephthalate, polylactic acid, cellulose, polyvinyl chloride, orpolyamide.

Embodiment 48

A panel according to embodiment 45 or embodiment 46, wherein the fibersare glass, hemp or flax.

Embodiment 49

A panel according to any of embodiments 45-48, wherein the one or morebinders of the sprayable mixture are selected from a rubber polymer(e.g., a styrene butadiene copolymer) and a plastic polymer (e.g., anacrylic polymer).

Embodiment 50

A panel according to any of embodiments 45-49, wherein the facing layeris substantially scattering for light in the wavelength range of 400-700nm.

Embodiment 51

A panel according to any of embodiments 45-50, wherein the facing layerhas an absorption coefficient of less than 0.5 for acoustic frequenciesin the range of 100 Hz to 10,000 Hz.

Embodiment 52

A panel according to any of embodiments 45-51, wherein the basestructure and the facing layer each independently have an airresistivity, and the air resistivity of the facing layer is equal to orless than the air resistivity of the base structure.

Embodiment 53

A panel according to embodiment 52, wherein the air resistivity of thefacing layer is in a range of about 1 to about 2000 kPa·s/m², e.g.,about 10 to about 1000 kPa·s/m², or about 100 to about 500 kPa·s/m².

Embodiment 54

A panel according to any of embodiments 45-53, having an NRC of at leastabout 0.3, e.g., at least about 0.35, at least about 0.4, or at leastabout 0.45.

Embodiment 55

A panel according to any of embodiments 45-53, having an NRC of at leastabout 0.5, e.g., at least about 0.6, or at least about 0.7, or at leastabout 0.8.

Embodiment 56

A panel of any of embodiments 45-55, wherein the NRC of the panel is atleast about 70% (e.g., at least about 80%, or at least about 90%, or atleast about 95%) of the NRC of the base structure independently.

Embodiment 57

A panel according to any of embodiments 45-56, wherein a thickness ofthe facing layer is within the range of about 0.25 mm to about 20 mm,e.g., about 0.25 mm to about 15 mm, or about 0.5 mm to about 10 mm.

Embodiment 58

A panel according to any of embodiments 45-57, wherein a width of thepanel is within the range of about 12 to about 60 inches, e.g., from 23to 25 inches or from 46 to 50 inches, and a length of the acoustic panelis within the range of about 12 to about 144 inches, e.g., from 23 to 25inches or from 46 to 50 inches.

Embodiment 59

A panel according to any of embodiments 45-58, wherein the facing layercomprises fibers in an amount within the range of about 10 wt. % toabout 50 wt. %, e.g., about 10 wt. % to about 45 wt. %, or about 15 wt.% to about 40 wt. %.

Embodiment 60

A panel according to any of embodiments 45-59, wherein the facing layercomprises binder and pigment in a combined about within the range ofabout 40 wt. % to about 90 wt. %, or about 50 wt. % to about 90 wt. %,or about 55 wt. % to about 85 wt. %.

Embodiment 61

A panel according to any of embodiments 45-60, wherein the outward majorsurface of the base structure comprises a localized paint.

Embodiment 62

A panel according to embodiment 61, wherein the color of the outwardmajor surface is white or black.

Embodiment 63

A panel according to any of embodiments 45-62, wherein the outward majorsurface of the base structure does not comprise a localized adhesive.

Embodiment 64

A panel according to any of embodiments 45-63, wherein neither of apigment and an adhesive is localized on the outward major surface of thebase structure.

Embodiment 65

A panel according to any of embodiments 45-64, wherein the exteriormajor surface of the facing layer comprises a localized paint.

Embodiment 66

A panel according to any of embodiments 45-65, wherein the color of theexterior major surface is white or black.

Embodiment 67

A panel according to any of embodiments 45-66, wherein the panel isresistant to sagging.

Embodiment 68

A panel according to any of embodiments 45-67, made by a methodaccording to any of embodiments 1-44.

Embodiment 69

A panel system comprising:

-   -   a plurality of support beams arranged in a support grid so as to        form a plurality of grid openings in the support grid; and    -   a plurality of panels respectively aligned with the openings of        the support grid, the plurality of panels including a first        acoustic panel according to any of embodiments 45-68, wherein        the first acoustic panel is oriented such that the exterior        major surface of the facing layer is facing an interior space        adjacent to the support grid.

Embodiment 70

The panel system according to embodiment 69, wherein the panel system isa ceiling system and the support grid is a ceiling grid.

Embodiment 71

The panel system according embodiment 69 or embodiment 70, wherein eachof the plurality of panels is an acoustic panel according to any ofembodiments 45-68.

We claim:
 1. A method for preparing an acoustic panel comprisingproviding a base structure having one or more edges, an outward majorsurface having a total area, and an inward major surface opposing theoutward major surface, the base structure having independently a noisereduction coefficient (NRC) of at least about 0.3, wherein the basestructure comprises a plurality of perforations extending from theoutward major surface towards the inward major surface, the plurality ofperforations occupying an area of the outward major surface within therange of about 0.1% to about 10% of the total area of the outward majorsurface; and disposing directly against the outward major surface of thebase structure a sprayable mixture comprising a plurality of fibers; oneor more binders; and a dispersive medium; and drying the disposedmixture to provide a facing layer disposed on the outward major surfaceof the base structure, the facing layer having an exterior major surfaceopposing the outward major surface of the base structure.
 2. A methodaccording to claim 1, wherein the base structure comprises one or moreof mineral wool, fiberglass, gypsum, wood fiber, paper, cellulose fiber,wet-laid felt, and foam; one or more fillers; and one or more binders;present in the base structure in a combined amount of at least about 85wt. %, or at least about 95 wt. %, or at least about 97.5 wt. %, or atleast about 99 wt. %.
 3. A method according to claim 1, wherein theaverage depth of the perforations is at least about 3 mm.
 4. A methodaccording to claim 1, wherein the base structure has a thickness withinthe range of about 2 mm to about 50 mm.
 5. A method according to claim 1wherein the base structure has independently a noise reductioncoefficient (NRC) of at least about 0.5.
 6. A method according to claim1, wherein the fibers are of polyester, polypropylene, polyethylene,polyethylene terephthalate, polylactic acid, cellulose, polyvinylchloride, or polyamide.
 7. A method according to claim 1, wherein thefibers are of glass or natural fibers.
 8. A method according to claim 1,wherein the fibers have an average length within the range of about 0.5mm to about 12.5 mm and an average linear mass density within the rangeof about 0.1 denier (D) to about 25 D.
 9. A method according to claim 1,wherein the fibers are present in the sprayable mixture in an amountwithin the range of about 0.1 wt. % to about 10 wt. %.
 10. A methodaccording to claim 1, wherein the fibers are present in the sprayablemixture in an amount within the range of about 1 wt % to about 30 wt %.11. A method according to claim 1, wherein the one or more binders ofthe sprayable mixture include one or more binders selected frompolyurethanes, polyacrylates, styrene-acrylate copolymers,styrene-ethylene-butadiene-styrene block copolymer (SEBS),styrene-butadiene copolymers, poly(vinyl acetate) (PVAc),poly(ethylene-vinyl acetate) (EVA), ethylene-vinyl chloride copolymers,polystyrene, poly vinyl alcohol and starches.
 12. A method according toclaim 1, wherein the one or more binders are present in the sprayablemixture in a combined amount within the range of about 0.5 wt. % toabout 30 wt. %.
 13. A method according to claim 1, wherein thedispersive medium comprises one or more of a viscosity modifier and adispersant, present in the dispersive medium in a combined amount withinthe range of about 0.1 wt. % to about 15 wt. %; and water, present inthe dispersive medium in an amount within the range of about 85 wt. % toabout 99 wt. %.
 14. A method according to claim 1, wherein the totalamount of water in the sprayable mixture is in the range of about 20 wt% to about 98 wt %, e.g., about 50 wt. % to about 98 wt. %.
 15. A methodaccording to claim 1, wherein the sprayable mixture further comprises apigment.
 16. A method according to claim 1, wherein the sprayablemixture comprises a plurality of fibers having an average length withinthe range of about 0.5 mm to about 15 mm and an average linear massdensity within the range of about 0.1 D to about 25 D, present in thesprayable mixture in an amount within the range of about 0.1 wt. % toabout 10 wt. %; a binder, present in the sprayable mixture in an amountwithin the range of about 0.5 wt. % to about 30 wt. %; a dispersivemedium, present in the sprayable mixture in an amount within the rangeof about 80 wt. % to about 99 wt. %, comprising one or more of aviscosity modifier and a dispersant, present in the dispersive medium ina combined amount within the range of about 0.1 wt. % to about 15 wt. %;and water, present in the dispersive medium in an amount within therange of about 85 wt. % to about 99 wt. %.
 17. A method according toclaim 1, wherein the total amount of the binder, fibers, dispersivemedium, and pigment is at least about 85 wt. % of the sprayable mixture.